1. Technical Field
The present invention generally relates to improved means for testing integrated circuits and in particular to test circuits for integrated circuit chips. Still more particularly, the present invention relates to an improved means for testing integrated circuits by bypassing failed elements.
2. Description of the Related Art
In developing analog modules involving complex blocks of circuitry there is significant risk that a design defect will cause a block to be inoperative. If so, the initial fabrication pass of the module may be totally useless, adversely affecting the development schedule of the products depending on the module.
Even if the module is tested, often these tests will not show which of the component circuits of the module is defective, or if more than one component is defective. Because the module components are often connected in series, if one component of the module is defective, it is impossible to test any components downstream of the known defective component.
This makes the process of testing the module extremely difficult. While it may be possible to repair a defective circuit component of the module, until it is repaired, it is impossible to even test the components downstream of the defective module. Since this is the case, it is difficult to determine if the module is even worth repairing until after too much time and expense has already been invested. It would therefore be desirable to have a means to bypass a defective component in order to test other components of the module.